Keyboards are used for the manual input of data to a wide variety of devices. Well-known devices with keyboard inputs include typewriters, computers, calculators, telephones, Personal Digital Assistants, television remote controls, cable set-top receivers, satellite receivers, VCRs, GPS receivers, kitchen appliances, information appliances and games. The data inputted by keyboards include numbers, text, and instructions.
Keyboards fall into two broad classifications. The first classification descended from early typewriters is a substantially rectangular array including a large number of keys. This first type of keyboard assigns an individual key to each character in the alphabet and includes additional keys for numbers and often instructions. The second classification descended from early touch-tone telephones includes a smaller number of keys. This second class has commonly twelve keys arranged in four tiers of three key rows. Both types of keyboards may be used to enter alphanumeric data such as text, numbers, and instructions. By necessity the second class of keyboard assigns multiple characters to each key.
The first typewriters patented in 1868 arranged the keys in alphabetic order. The mechanical nature of these early typewriters caused many common letter combinations to jam. This jamming problem led to the development of the now standard QWERTY keyboard. There have been many alternatives to the QWERTY keyboard proposed, but none have found widespread adoption. This is primarily because of the necessity of retraining operators who with experience are able to touch type.
The second broad classification of keyboards sometimes called data-entry keyboards derive from the first touch-tone telephone keyboard developed by Bell Labs in the 1960's. Such keyboards include a array of twelve keys arranged in four tiers of three keys each. A single digit is assigned to each key. This type of keyboards is very efficient for the entry of numerical data. When such keyboards are used for entry of alphanumeric data such as names, text, and addresses problems arise. Twelve keys are more than is necessary for numerical data, however, other schemes must be used with character sets of twelve or more members. All such systems require the assignment of multiple characters to each key.
The earliest system for imputing alphanumeric data was the now standard telephone touch pad. In this scheme the 2 key is also A, B, and C. 3 is also D, E, and F and so on. The letters Q and Z were not included in then standard touch pad. A shift key (usually * or #) is needed to select the proper letter as most keys have three letters and a number. The touch pad allows the input of alphanumeric data, but is slow and difficult to use. This is because the human mind does not order data in this manner. The result is that the user of such a system must often resort to reciting the alphabet each time they wish to input a letter. Mistakes are frequent and most users loathe the process. The method is unfamiliar to those trained to touch type both due to the different location of the keys and the lack of one-to-one correspondence between keys and symbols.
An alternative to the telephone touch pad method is the multiple pressing of a single key. This method is frequently used in consumer electronic devices such as VCR's, TV's, cellular phones, fax machines, and telephone answering machines. A single key (often an arrow) is pressed once for A, twice for B, and so on. Frequently, the selected letter is highlighted as one scrolls through the alphabet. Usually this system is only used for short text such as a first name or station call letters. Most users become quickly discouraged if more than a few letters are needed.
A third solution has been to try and link the thinking process with the input of data. In such systems each key is pressed once and a look-up table or dictionary is used to determine what word the user is trying to convey. In such systems each key represents more than one letter and the software attempts to resolve the inherent ambiguity. In more advanced systems artificial intelligence allows customization to a particular user. A system of this sort as described in U.S. Pat. No. 5,953,541 to Martin et al. Martin and similar systems have not met with wide scale adoption due to the highly ambiguous nature of a key input equivalent to three or more letters. The mix-matching of letters and words generated by the system may be enough to force users into temporary dyslexia.
The above difficulties have led to the development of touch screens and pen computing. In such systems letters are written by hand with a stylus onto a digitizing pad. Software converts the resulting bitmap data into text. Such software commonly called gesture recognition software is in an ongoing state of development. This type of system is frequently used in Personal Digital Assistant (PDA) or palm computers. The difficulty is that the recognition software requires substantial memory resources and is prone to error.
Each of the above systems was designed with the Latin alphabet in mind with English as the language in of choice. In the majority of the world, however, English is at best a second language. The problems are multiplied if Arabic or Hebrew is attempted to be inputted with any of these keyboards. When Chinese, Korean, or Japanese is tried the problems become near insurmountable. There is a long-standing need for a truly international twelve key keyboard.
Each of the above twelve key keyboards has the additional problem of having an extremely steep learning curve. Due to their unfamiliar nature and individual differences these keyboards are hard to learn and even harder to improve ones skills at. The many VCR's that still flash 12:00, evidence this problem.